Errors during setup on OSX

[aels]

On installation attempt I get

go get github.com/haccer/subjack
# github.com/miekg/dns
../../go/src/github.com/miekg/dns/dnssec_keyscan.go:149:18: undefined: ed25519.SeedSize
../../go/src/github.com/miekg/dns/dnssec_keyscan.go:152:8: undefined: ed25519.NewKeyFromSeed
../../go/src/github.com/miekg/dns/dnssec_privkey.go:86:24: p.Seed undefined (type ed25519.PrivateKey has no field or method Seed)

on OSX Mojave 10.14.5
go version go1.12.5 darwin/amd64

(master) % go env                           ~/www/tools/subjack
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/User/Library/Caches/go-build"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/User/go"
GOPROXY=""
GORACE=""
GOROOT="/usr/local/Cellar/go/1.12.5/libexec"
GOTMPDIR=""
GOTOOLDIR="/usr/local/Cellar/go/1.12.5/libexec/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/kt/x9cp3xx52wg9xt7y61187fbh0000gn/T/go-build305441602=/tmp/go-build -gno-record-gcc-switches -fno-common"

Any things I need to try?